Watch movement construction

ABSTRACT

A watch movement construction wherein two bridges and two frame plates for bearing or accommodating a plurality of the movement elements wherein the bridges and frame plates are held apart in fixed relative positions by two spacers and bridge screws threaded into the spacers. The bridges and frame plates are made flat and are provided at predetermined positions with cut-outs or mount holes for easy assembly of the construction and for receiving the staffs of rotary members of the construction. The cut-outs and mount holes can be formed by simple pressing or drilling operations.

United States Patent [191 Maeda et al.

[111 3,754,390 Aug. 28, 1973 WATCH MOVEMENT CONSTRUCTION [75 Inventors:Katsutoshi Maeda, lchikawa-shi;

Norio Kobayashi, Tokyo, both of FOREIGN PATENTS OR APPLICATIONS 558,6658/1923 France 58/59 Japan Primary Examiner-George H. Miller, Jr. [73Assignec: Kabushik i Kaisha Daini Seikosha, y- Buml 3L Tokyo, Japan 221Filed: May 25, 1972 [5 TRA T 21 A N 256 752 A watch movementconstruction wherein two bridges 1 pp 0 and two frame plates for bearingor accommodating a plurality of the movement elements wherein the plbridges and frame plates are held apart in fixed relative May 27, 1971Japan 46/36458 positions by two spacers and bridge screws threaded intothe spacers. The bridges and frame plates are made [52] U.S. Cl. 58/7,58/59 flat and are provided at predetermined positions with [51] Int.Cl. G04b 13/00, G04b 33/00 cut-outs or mount holes for easy assembly ofthe con- [58] Field of Search 58/7, 59, 139, 140 R struction and forreceiving the staffs of rotary members i of the construction. Thecut-outs and mount holes can [56] References Cited be formed by simplepressing or drilling operations.

UNITED STATES PATENTS 4 Claim. 7 Drawing Flam 673,053 4/l90l Henderson58/7 3,492,808 2/1970 Wuthrich ..-58/59 5 6 i 55 i 'i i 7 i a d 9 I Z i66 v3?) I 52 2 '5 x =2. 1 9 5b b 7a 7b 5C i t I [Cf- 6c 5-4 9c 7b 34 261 7b 8c 4 8c 8C 5 8(. Yb 9,,

Patented Aug. 28, 1973 3,754,390

2- Sheets-Sheet Iv I II Patented Aug. 28, 1973 3,754,390

' 11 Shoots-Sheet 1.,

F/G. 4 l8 H I MU 14W WATCH MOVEMENT CONSTRUCTION BACKGROUND OF THEINVENTION frame .plate and the other end thereof bearing on a bridge.The frame plate and bridge each has its surface drilled and polished ina milling process and set off so as to accommodate the pallet fork orother mechanical elements of the watch. Moreover, the frame plate orbridge is bored to receive screws or pins in order to fix back geartrains after assembling the frame plate and bridge. These machiningsteps disadvantageously result in precise and complex machining of theparts and the expenditure of much working time.

SUMMARY OF THE INVENTION A principal object of the present invention isto provide an improved watch movement construction eliminating theabovementioned drawbacks and capable of being easily and assuredlyassembled.

A watch construction according to the present invention comprises twobridges and two frame plates. The bridges and frame plates are made offlat plates and provided at predetermined positions with cut-outportions or mount holes for hearing elements of the watch and to alloweasy access for assembly of the construction.

The bridges and frame plates are easily made by molding press or byautomatic lathing tools. The bridges are fixed spaced at predetermineddistances, by spacers, so that the watch movement construction according to the present invention makes it easy to position or carry theelements of the watch movement eliminating the use of any particularjigs or the requirement of turning over the movement.

The two spacers are constructed with flat surfaces normal to alongitudinal axis thereof. These flat surfaces are axially spaced andthe two bridges and two frame plates rest on respective flat surfacesand extend generally parallel. The outermost bridge and outermost frameplate are provided with openings into which the spacers extend. The flatsurfaces are spaced axially on the spacers determining the spacing amongthe bridges and frame plates and therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned objects andfeatures of the present invention will be more fully described inconnection with the accompanying drawings in which:

FIG. 1 is a schematic longitudinal sectional view showing a watchmovement construction according to the present invention;

FIG. 2 and FIG. 3 are perspective plan and bottom or backside viewsrespectively of the watch movement construction of FIG. I;

FIG. 4 is a fragmentary section view taken on a section line 4-v-4 ofFIG. 2;

FIG. 5 is a fragmentary section view taken on a section line 5-5 of FIG.4;

FIG. 6 is a fragmentary section view taken on a section line 6--6 ofFIG. 4; and

FIG. 7 is an explanatory diagrammatic view illustrating the relationshipbetween a second plate and a fork pallet of the watch movement in FIG.1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIGS. 1-3,there is shown a watch construction wherein first and second bridges land 2 define spaces into which mechanical parts of the watch areaccommodated. The bridges and frame plates 3, 4 are provided with mountholes 6, 6a, 6b, and 6c, into which is inserted a spacer 5 fixing thebridges and frame plates at predetermined distances therebetween. Inthis embodiment, two spacers 5 are provided to assure the stableattachment of the bridges and plates as shown in FIG. 2. Moreover, thebridges and frame plates are provided at predetermined positions withholes 7, 7a and 7b functioning as bearings for the staffs of the gearsand with cut-out portions 8, 8a, and 9, 9a for housing the mechanicalelements.

The spacers 5 have at one end a flanged portion 5a engaging with thefirst and second bridges I and 2 and being axially thick enough toseparate one from the other. Further, the spacers have at the other enda smaller diameter portion 5b loosely engaging with a hole 6b of thesecond frame plate 4 and a smaller diameter portion 5c also looselyengaging with a hole 6c of the first frame plate 3, and has threadedbore at its central portion to receive a correspondingly threaded screw11 for fixing the plates. Screws ll fix the frame plates 3 and 4together with the spacers 5.

According to the embodiment of the present invention, a balance wheel 19with its staff is carried on bearing means each mounted on the firstbridge I and the first frame plate 3. A pallet fork l6 reciprocated bythe balance wheel 19 is carried on the first bridge 1 and the secondframe plate 4. The second frame plate 4 has a cut-away portion 9b forhousing therein a top portion 16a of a pallet fork 16. The edges 9a ofthe cut-away portion also act as stop members for limiting the angu larmovement of the pallet fork 16 (FIG. 7). The gear trains, that is, anescapement wheel 15, and third and fourth wheels 13, 14 with theirstaffs are also rotatably carried on the first bridge 1 and the secondframe plate 4' According to the present invention, mechanical parts ofthe watch are assembled in the following steps to constitute the watchmovement construction. First, the spacer 5 is inserted into the mounthole 6 provided on the first bridge 1 and is caulked thereto. The secondbridge 2 has inserted into it the spacer through the hole 6a thereof tothe extent that the second bridge 2 rests against the flanged portion"5a of the spacer so as to be spaced from the first bridge 1. Prior tothe abovementioned step, the third wheel 13 is mounted on the firstbridge I.

I Next, a bearing block 36 for rotatably bearing a winding stem 40 in acavity thereof is secured to the first bridge I with its integralprojections 36a and 37b fixed into the bearing openings 7 as shown inFIG. 4. After finishing the above steps, the fourth wheel 14, theescapement wheel 15, and the fork pallet 16 are mounted through thesecond bridge 2 on the first bridge 1, while the center wheel 12 ismounted on the second bridge 2. The winding stem 17 and a setting leverpin 18 are set at predetermined positions respectively, as shown inFIGS. 4 and and these are assembled with the bearing block 36 before itis mounted on the assembly.

The second frame plate 4 is then mounted by inserting into the mounthole 6b thereof the portion 5b of the spacer 5 and by setting each staffof the gear train on the corresponding bearing mount. After setting thesecond frame plate 4, the balance wheel 19 is mounted. Next, a clutchlever 21 is mounted on the second frame plate 4 with a crown wheel 22 asshown in FIG. 4. A minute wheel 24 is then disposed on a predeterminedposition, as shown in FIG. 6, and its pivot is press fitted into anopening in the plate 4. After the mount hole 60 of the first frame plate3 has inserted the spacer 5 thereinto and the first frame plate 3 hasthe staffs fitting into the corresponding bearing mounts, a bridge screw11 is threaded into a threaded bore of the spacer to fix the first andsecond frame plates 3 and 4, respectively.

An hour wheel pinion 25 is mounted on the staff of the center wheel 12and an hour wheel 26 is also mounted thereto. Next, a setting lever 27'is inserted through a cut-away in the plate 4 and holds a lever pin 18in place and is secured by a setting lever spring which is fixed to thefirst frame plate 3 by a screw 29 threaded into an internally threadedsleeve as shown in FIGS. The setting lever pin is mounted in the bearing36 before mounting thereof on the plate 4. A barrel drum 31 is insertedlaterally of the bridges and plates and is set at a predeterminedposition between the first bridge 1 and the second frame plate 4 asshown in FIGS. 1 and 2.

The winding stem bearing block 36 may be made of plastic as an integral,precision injection molded unit that has accurately molded cavities andopenings therein for receiving those members of the watch movement thatit carries. The winding stem 17 is assembled with the bearing 36 in acavity thereof prior to mounting of this bearing on the bridge andplate. The winding stem extends axially out of the bearing 36 and theassembly shown in the drawings.

In assemblying the winding stern bearing the winding stem is insertedinto its cavity through a winding stem pinion 17a that is received inits own cavity in the bearing 36 and has a central opening provided withinternal surfaces complementary to those of the winding stem that drivesit.

The winding stem 17 is provided with a collar 17b and a portion 17cspaced axially from the collar and has a major diameter. The settinglever 27 has a bent portion that extends through a cut-out in the plate4 into the cavity of the winding stem and is disposed between the collar17b and the portion 17c of major diameter so that it maintains thewinding stem from moving axially outwardly of the bearing.

An innermost end postion 17d of the winding stem is supported forrotation by a bearing pin 36a extending into the cavity of the windingstem. This bearing pin 36a is inserted into position through an openingin the plate 4 and is held therein.

Finally a rachet wheel 34 is inserted in a barrel staff 32, the axle 33of which is in turn fixed to the first bridge 1 by a spring keeper orE-ring 35.

The watch movement construction according to the present invention hasmany advantages or features over the conventional ones as follows: thesecond bridge 2 is assuredly maintained spaced apart from the firstbridge 1 while the second frame plate 4 is also maintained spaced apartfrom the first frame plate 3 by the spacers 5 with the first and secondframe plates 3, 4 both fixed to the spacer 5 by the bridge screws 11.The cut-out portions can be formed by changing the configurations of thefirst and second frame plates 3 and 4 as shown by dotted lines P in FIG.3. The clutch lever 21 is included between the first and second frameplates 3,4. The first frame plate 3 also functions as a spring for theclutch lever 21 (FIG. 4). The assembling of the complete barrel drum 31,with the ratchet wheel 34 may be taken apart without any disturbance ofthe remaining parts. It is possible to easily clean the watch movement(FIGS. 1 and 2). The provision of the hole 8 allows the second handpinion to be connected to the staff 12a of the center wheel 12 and makeseasy the power transmission to the minute and hour hands (FIG. 1). Nosurface machining, bending, off-setting or milling are required therebysaving much time. The provision of holes 8a on the second bridge 2 forthe fourth wheel 14, the escapement wheel 15, and the pallet fork 16prevent the inclination of these wheels during assembling and makes easythe assembling thereof (FIG. 1). Cut-out portion 9 provided on thesecond frame plate 4 serves as limiting means for limiting theoscillation of the pallet fork 16, thereby dispensing with theconventional banking pins. The back gear train is assembled withoutturning over the movement because the assembling can be always carriedout with the bridges down.

What we claim and desire to secure by Letters Patent 1. A watch movementconstruction comprising, two flat bridges and two flat frame plates, twoseparate spaced spacers each having bearing surfaces axially spacedthereon on which the two bridges and the two frame plates bearindividually and are held spaced apart extending generally parallel,each bridge and each frame plate having cut-outs in predetermined placesincluding some of which are in registry to provide access to a spacetherebetween and having a plurality of spaced bearing openings forreceiving therein respective staffs of a plurality of rotatable elementsof a watch movement, each spacer having a threaded bore, and a threadedscrew holding an outermost one of the frame plates on said spacer.

2. A watch movement construction according to claim 3, including apallet fork oscillatable on said out- 'ermost frame plate, and saidoutermost frame plate having a cut-out within which said pallet forkoscillates, and the surfaces defining the cut-out being disposed tolimit the amplitude of oscillation of said pallet fork.

3. A watch movement construction according to claim 1, in which saidoutennost frame plate is provided with a plurality of mount holes foruse as bearings for staffs of gears of a back gear train.

4. A watch movement construction according to claim 1, in which saidspacers each have a longitudinal axis and said bearing surfaces are flatand disposed in planes substantially normal to the longitudinal axisthereof, and said bearing surfaces are disposed axially spaced on thelongitudinal axis at axial distances determining desired axial spacingof said bridges and said frame plates.

1. A watch movement construction comprising, two flat bridges and twoflat frame plates, two separate spaced spacers each having bearingsurfaces axially spaced thereon on which the two bridges and the twoframe plates bear individually and are held spaced apart extendinggenerally parallel, each bridge and each frame plate having cut-outs inpredetermined places including some of which are in registry to provideaccess to a space therebetween and having a plurality of spaced bearingopenings for receiving therein respective staffs of a plurality ofrotatable elements of a watch movement, each spacer having a threadedbore, and a threaded screw holding an outermost one of the frame plateson said spacer.
 2. A watch movement construction according to claim 3,including a pallet fork oscillatable on said outermost frame plate, andsaid outermost frame plate having a cut-out within which said palletfork oscillates, and the surfaces defining the cut-out being disposed tolimit the amplitude of oscillation of said pallet fork.
 3. A watchmovement construction according to claim 1, in which said outermostframe plate is provided with a plurality of mount holes for use asbearings for staffs of gears of a back gear train.
 4. A watch movementconstruction according to claim 1, in which said spacers each have alongitudinal axis and said bearing surfaces are flat and disposed inplanes substantially normal to the longitudinal axis thereof, and saidbearing surfaces are disposed axially spaced on the longitudinal axis ataxial distances determining desired axial spacing of said bridges andsaid frame plates.